Intake heater



July 30, 1929.

C. R. GREUTER INTAKE HEATER Filed March 1925 INVENTOR mflm ATTORNEYS Patented July 30, 1929.

' UNITED srsrss CHARLES R. GBEUTER,

or CHICAGO, ILLINOIS.

INTAKE HEATER.

Application filed March 7, 1925. Serial No. 13,879.

This invention relates to intake heaters for internal combustion engines and particularly to such heaters applied to engines of the valve-in-the-head type.

In order to secure the desired port areas with complete accessibility and attractive appearance it is desirable to place the intake manifold on one side of the cylinder block and the exhaust manifold on the opposite side. When this is done, it has hereto fore been found diflicult to employ the exhaust gases, or part of them, in an intake heater. In prior structures recourse was had to external piping, which did not give the desired free flow of exhaust gases to the heater and which not only detracted from.

the appearance of the engine, but was in the way when repairs or adjustments were necessar The present invention avoids all these difficulties and secures a peculiarly efficient heater by surrounding a portion of the inlet manifold with a heating jacket and connecting the two ends of the heating jacket to two corresponding ports, each port leading from the main exhaust port of a.correspond ing one of two cylinders. 'These branch ports thus extend across the cylinder head to the inlet side of the engine, and they may conveniently be connected to the exhaust ports of two adjacent cylinders. The heating jacket and its connections to the branch ports may be cast integrally with the inlet manifold, thus producing a very neat and simple structure devoid of piping.

Since the two cylinders, whose exhaust ports are connected by the branch ports to the opposite ends of the heating jacket, do not exhaust simultaneously, a part of the exhaust from each cylinder reaches the exhaust manifold through the exhaust port of the other cylinder, passing on the way through the branch ports and the heating jacket. The flow through the jacket is thus alternating in direction, so that the heating effect throughout the length of the heating jacket is uniform. Moreover, the exhaust passage offered through the heating jacket may be made very free, so that any desired portion of the exhaust gases from these two cylinders may be made to pass through the heating jacket in preference to passing directly through the main exhaust port to the exhaust manifold.

From the above it follows that not only does the design lead to a simple, self-contained structure, but it permits a structure which may be so varied in its specific form as to give any desired heating effect. Connection of the heating jacket to two cylinders is suf- 0 ficient, but obviously the principle of the invention might be extended by connecting the jacket in the same way to more than two cylinder exhaust ports.

The preferred embodiment of the invention is illustrated in the accompanying draw- 1ngs as applied to a multi-cylinder engine in which each group of four cylinders is fed by a single carburetor, so that the inlet manifold supplies four cylinders. The valves might be actuated in any suitable manner, but in the example illustrated they are actuated directly by cams on an overhead cam shaft. Obviously more than four cylinders might be connected to a single manifold, if desired.

In the drawings,

Fig. 1 is a fragmentary plan view partly in section, showing the cylinder head, the cam shaft, its bearings and housing being removed.

Fig. 2 is a section on the line 2-2 of Fig. 1, but shows the cam shaft and its housingin place. j

The cylinder head 6 is provided with the usual combustion spaces 7 to each of which leads an inlet port 8 provided with an inlet valve. 9 of the ordinary poppet type. The inlet valve stems are shown at 10 and are guided and actuated in the same manner as the exhaust valves which will be hereinafter described.

The exhaust ports are shown at 11 and are controlled by poppet exhaust valves 12. Each valve is guided and actuated by means of a stem 18 carrying at its upper end a head or tappet 14 whose exact construction is not material to the present invention. The tappet 14 is confined by a guide 15 which also serves to house the valve spring 16. Each tappet 14 is engaged directly by a corresponding cam 17 on the oam shaft 18. This camshaft turns in bearings'not shown in detail in the drawing and not material to the present invention. The valve mechanism will be recognized as conforming in its main features with known practice.

The exhaust manifold is shown at 19 and preferably is so arranged that a single manifold receives the exhaust from all the cyl 11 ings indicated at 29 are merely core holes the other connected cylinder.

. dismounting the engine. pled with its marked efficiency, render 1t a inders of the engine through a series of exhaust branches 20 which connect with the various exhaust ports 11.

The inlet manifold 21 in the particular example illustrated, supplies four cylinders through the branch connections 22 which communicate with the inlet ports 8. Thecarburetor, not shown, attaches to the flange 23 and feeds the inlet manifold through the port 24;. The middle portion of the manifold 21 is surrounded by a shell 25 which provides an annular jacket space 26. This communicates through the branch connections 27 with branchports 28-which extend from the inlet side of the head to the main exhaust ports 11 of the middle two cylinders of the group fed. by the inlet manifold. The shell 25, which encloses the jacket space 26, and the connections 27 are cast integrally with the inlet manifold, so a single unitary structure is provided. The threaded openand are plugged. A bafile or partition 30 is i provided across the jacket space 26 at the side towardth'e cylinder for the purpose of ensuring the flow of exhaust gases on all sides of the ,inlet manifold. In Fig. 1 a sparkplug is shown at 31 and a portion of the cylinder block at 32.

When the engine is running, the jacket space 26 will offer passage to exhaust gases flowing from one of the connected cylinders through the heater to the exhaust passage of The battle forces the gases to flow on all sides of the exhaust manifold and sincethe flow is alternate-in direction, the action of the heater is uniform throughout its length.

- :The structure is simple and inexpensive to construct, attractive in appearance, and since it avoids allv extra connections, imposes no difliculties or extra labor in assembling and These facts, cou

peculiarly desirable construction.

WVha-t is claimed is:

1. The combination of a multicylinder internal combustion engine having its cylindersarranged in, line, with inlet and exhaust ports terminating respectively in opposite sides of the-row of cylinders, and having branch-ports formed in the walls of the cylinder structure and leading from the exhaust ports of a plurality of cylinders to the inlet side. of the engine; an inlet manifold connected to said engine and having branches leadingv to inlet'ports; and a duct for exhaust gases connected exclusively to said branchxports and in heat exchanging rela-- tion with said inlet manifold.

from the exhaust ports of two cylinders to the inlet side of the engine; an inlet manifold connected with said inlet ports; and a heater duct connected exclusively wit-h said branch ports, said duct being in heat conducting relation with said inlet manifold anal connected with said branch ports at its en s. 3. The combination of a multicylinder in ternal combustion engine having its cylinders arranged in line, with inlet and exhaust ports terminating respectively in opposite sides of the row ofv cylinders, and having branch ports formed in the walls of. the cylinder structure and leading from the exhaust ports of a. plurality of cylinders to the inlet side of the engine; and aunitary inlet manifold connected with said engine and including a main supply passage with branches leading to inlet ports and a. separate heater passage communicating exclusively with said branch ports.

4. The combination of a multicylinder internal combustion engine having its cylinders arranged in line, with inlet and exhaust valves mounted in the cylinder heads, inlet ports leading from one side of the row of cylinders to the inlet valves, exhaust ports leading to the other side of the row of cylinders from the exhaust valves, and branch ports extending from two exhaust ports to the inlet side of the row of cylinders; and a unitary inlet manifold connected with said engine and including a main supply passage with branches leadingto inlet ports and a separate heater passage communicating exclusively with said branch ports.

5. The combinationof a multicylinder internal combustion engine having its cylinders arranged in line, with inlet and exhaust valves mounted in the cylinder heads, inlet ports leading from one side of the row of cylinders to the inlet valves, exhaust ports leading to the other side of the row of cylinders from the exhaust valves, and branch ports extending from two exhaust ports to the inlet side of the row of cylinders; an inlet manifold; and a heater for said manifold connected exclusively with said branch ports. I

In testimony whereof I have signed my name to this specification.

CHARLES R. GREUTER. 

